Windows Service versus API - winforms

Can anyone tell me the difference between a Windows Service and API?

That's a very odd question which leads me to suspect its not actually the one you want to ask...
API is Application Progammer Interface or thereabouts - as generically as possible, its a means for a developer to interface with something by means of software (the something could be another application e.g. Word, or a Web Service or the operating system or a bit of hardware).
A Windows Service is an application that runs in a particular manner on the Windows OS - very roughly - an application without an explicit UI running "in the background" launched when the OS launches (usually, but not necessarily) and independent of logged on users.
So you're comparing a particular type of application with a means of communicating between/with applications?

Related

Improve WPF Application Coldstart: Suggestions to run program when machine starts up

Is it possible to load your WPF application when the machine starts up? Our WPF application is taking 30 seconds on our existing client hardware, and we'd like to "hide" that by having our application startup when the machine is booted. But the fact that our application boots on startup should be invisible to the user.
How would we go about building such a thing? Is there a term to google that will provide a tutorial? It would be nice if there's a WPF specific-one we can grab.
Note: In case there's any moral qualms to this (since I agree that having 20 programs startup when your computer does is frustrating!), we're building software for a specialized industry who will be using their computer to run primarily our applications.
The easiest approach would be
make sure your big libraries are installed in the GAC
write a dummy app that uses (most of) those libs. Actually use them so they get loaded.
run the dummy on startup
make the dummy stop by itself, or keep it alive hidden
This would in no way interfere with the starting of the normal application. The benefit is that the libraries get loaded and jitted. The drawback that your app still needs to load & initialize.
Sasha had a few more tips not listed here, rebasing your modules, leveraging the prefetch facility and compression (UPX, yuk!).

Porting/Writing WPF application which launches external applications to Silverlight 4 out of browser

WPF launches certain method which calls external exe and waits , and then accesses a file which was an output of external exe. Assuming I would build this application with a consideration of porting to Silverlight 4 later what should I do ?
In order to do this you would need to go through Silverlight's COM automation. I'm sure there's some out-of-process COM server that you could use to start a process. But at that point you've already
limited your application to Windows
require full trust
will only work in "out of browser" mode
At that point, you really gotta ask whether or not it makes any sense to port to Silverlight. WPF is particularly suitable for the above scenarios. You can use ClickOnce to achieve a similar (actually, superior) client update experience and you won't have to jump through hoops to do something as simple as spawning an external process.

How to handle win32 services in windows 2000 platform

I ve designed a win32 service in windows XP its working fine. but the problem i'm facing is that it's not working properly in windows 2000 platform. that is stopping the service restarting the service. is there any setting or need to change in code to be done.
Is it possible you have used an API that was new on WinXP?
For an interactive applications you would get a popup about an unresolved import, if I recall correctly for services these are recorded in the system event log.
If it is hanging, take process dumps and feed them into a debugger with symbols (both Microsoft's and yours) configured. That will show you the stacks of the threads, and allow you to check for deadlocks.

Out of browser feature of Silverlight 3.0

Why and when somebody would take out the Silverlight application out of browser and run? As this is feature provided in Silverlight 3.
When the application is useful enough that you want to use it often and you don't want to depend on a browser or an internet connection, for example.
In Silverlight 4, out of browser applications will make even more sense since they can run with elevated permissions and do things such as accessing the local filesystem or running applications on the client machine: http://silverlight.net/getstarted/silverlight-4-beta/#whatsnew (search For Trusted applications)

"Out of browser" web application running at Start-Up?

I've become familiar with the new concept of "out of browser" web applications, supported in the recent Silverlight, JavaFX, Adobe AIR etc.
Listening recently to a podcast on the subject by Scott Hanselman, I've become aware that one of the purposes behind these new architectures is to allow for "desktop-application-feel". Also, I understand some (or all) of these allow for some offline access to a sandbox of resources. This really sounds as if these frameworks could be an alternative to "real" desktop applications, as long as the application does not require messing with the user's machine (i.e. access to peripherals, certain file IO, etc).
I have a very specific question. My application needs to run at start-up. Is it possible to do so using such a framework without requiring the user to download and run a certain executable?
For example, I could always direct the user to download a small EXE that will put a .lnk file in the start-up directory, but I want to avoid such a patch.
To summarize: is it possible to have an out-of-browser web application setup itself to run at start-up without requiring file download?
To further clarify, this question does not come from an "evil" place, but rather from trying to decide whether "out-of-browser" frameworks are indeed a proper alternative to a desktop application, for my specific requirements.
The BkMark example here shows how to start an application on startup using Adobe Air. So, yes it is possible.
So, here's the deal: web apps in general will have a security context around them, and by default won't have access to write to the filesystem (outside of a temp files), access the registry, etc.
One way is, as you said, have the user run something or configure it so the lnk is executed on startup.
Another way, and I think, more in line of what you want, is that the user can run the program himself, click some button in the application, and it's configured.
I know with Java you could do this, but the user has to allow full access to their system, because your app would need to change System configuration. Then you could just configure it (by writing a lnk to your WebStart JNLP in the Startup folder)
For Internet Exploder, Javascript apps do have write access to the disk.
For other (better-secured) browsers you will either need to have a download, or Adobe AIR.
Assuming you are building for Windows, launching an executable at startup can be done several ways.
For user session startup, you can achieve this either by putting a lnk file in the appropriate folder, or with a registry entry. For operating system startup, you can achieve this with a registry entry. There are several permutations:
run application once on boot (UI not allowed)
run application every boot (UI not allowed)
start service every boot according to policy set in registry
run application once on user session start
run application every user session
Since an out of browser application has UI I expect you mean run application every user session and in this case you may as well put an LNK file in the user's startup folder.
I just created a shortcut for an SL4 OOB application, and this was the Target of the shortcut:
"C:\Program Files (x86)\Microsoft Silverlight\sllauncher.exe" 2635882436.localhost
A search of my disk revealed that location 2635882436.localhost is a folder.
C:\Users\<mylogin>\AppData\LocalLow\Microsoft\Silverlight\OutOfBrowser\2635882436.localhost
I rather doubt an OOB app of any type could place a shortcut in the Startup folder unless you somehow obtained Full Trust.

Resources